11 Billion People By 2100 — And India Will Be More Populous Than China : Goats and SodaThe number of people on the planet is growing at the fastest rate in history. U.N. demographers say the world's population will be up by 4 billion at the end of the century.

Now, from a hundred missing people to 11.2 billion - that's the latest United Nations estimate for the number of people who will be on the planet by the end of the 21st century. It means the human population is growing at a rate never before seen in history. And as NPR's Jason Beaubien reports, billions of them will find themselves in what are now the poorest parts of the world.

JASON BEAUBIEN, BYLINE: Currently, there are 7.3 billion people on planet Earth, according to the United Nations. That number is expected to jump to 8.5 billion by 2030. These new predictions are 6 to 7 percent higher than earlier forecasts by the U.N.

ROBERT WALKER: The reason for that is that fertility rates, for the most part, are not falling as fast as previously anticipated.

BEAUBIEN: Robert Walker is the president of The Population Institute. He says rapid population growth poses huge challenges for already poor countries. It creates more competition for jobs, water and land. It heightens political friction and exacerbates food shortages. The West African nation of Niger, for example, is a regular recipient of international food aid. Yet Walker notes it has the highest fertility rate in the world, with, on average, 7.6 births per woman.

WALKER: If Niger is already having great difficulty feeding its population - when it's 18 million - what's going to happen in 35 years when its population is 68 million? Fifty-million more people. No one knows how Niger is going to feed itself, and the answer is it probably will not be able to feed itself.

BEAUBIEN: The report says the coming population boom will be most pronounced in Africa. The continent will account for three quarters of the additional 4 billion people who will be added by the end of this century. Africa has the highest birth rate in the world, with the average woman currently having 4.7 children compared to two-and-a-half globally.

The continent's population growth is also being driven, however, by improvements in health. Fewer kids are dying. AIDS is no longer a death sentence. And people on the continent are living longer than ever before. Outside of Africa, the other standout in this global population report is India. India is on track to surpass China as the most populous nation on Earth. And that's expected to happen in just seven years from now. Shenggan Fan, who runs the International Food Policy Research Institute here in Washington, says it's understandable that fertility rates are highest among poor people.

SHENGGAN FAN: When people are poor they need more support. Who support them? Their children, so that's why they have more children.

BEAUBIEN: And those kids tend to end up also being poor. He says the way to break that cycle is to attack the poverty problem. There are, of course, other ways to address the population boom. China addressed its rising numbers with the controversial one-child policy. India has set up sterilization camps. John Bongaarts, with the Population Council based in New York, says in many of the countries with the highest birth rates, governments could do a lot more to improve access to contraception.

JOHN BONGAARTS: Unfortunately, many governments in Africa are still reluctant. Government leaders much prefer to open new clinics or hospitals or airports rather than talk about sex and contraception.

BEAUBIEN: But Bongaarts points to two African nations that have greatly expanded access to family planning over the last decade - Ethiopia and Rwanda. In the 1980s, Rwanda had a second-highest birth rate in the world, with the average woman having eight or nine children. That rate's now been reduced by half. Ethiopia recently has made birth control available through rural clinics. Reported rates of contraception use in Ethiopia have risen from just 7 percent 10 years ago to 30 percent today. Bongaarts and others expect that programs like that will be what ultimately curb the rapid rise in global population. Jason Beaubien, NPR News.

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